Radial positioner, lock and rotary contacts for electromagnetic drill mount

ABSTRACT

For the rotary mount of a drill press support mounted on a rotary bearing plate having a diametrically extending open center mounted on a center pin extending upwardly from a fixed base, rotary electrical contacts in the center pin eliminating twisting of the wires therein and a radial positioner and locking means in the form of a radially extending lever offset from the drill on the drill press support and threaded to a yoke circumscribing the center pin and confining rollable members between spaced races on the pin for pressing the rotary bearing plate into locked engagement with the fixed base.

United States Patent Buck [54] RADIAL POSITIONER, LOCK AND ROTARY CONTACTS FOR ELECTROMAGNETIC DRILL MOUNT [72] Inventor: Eugene W. Buck, 110 Lansberry Court, Los Gatos, Calif. 95030 [52] U.S. CI ..408/76, 408/186 [5 l Int. Cl ..B23b 45/14 [58] Field of Search ..408/76, 72, 88, 186, 238

[451 July 18,1972

[56] Reterenees Cited UNITED STATES PATENTS 3,254,547 6/1966 Engelsted et al ..408/76 Primary Examiner-Gil Weidenfeld Attorney-Allen & Chromy ABSTRACT For the rotary mount of a drill press support mounted on a rotary bearing plate having a diametrically extending open center mounted on a center pin extending upwardly from a fixed base, rotary electrical contacts in the center pin eliminating twisting ofthe wires therein and a radial positioner and locking means in the form of a radially extending lever offset from the drill on the drill press support and threaded to a yoke circumscribing the center pin and confining rollable members between spaced races on the pin for pressing the rotary bearing plate into locked engagement with the fixed base.

11 Claims, 7 Drawing Figures Patented July 18, 1972 3,677,656

3 Sheets-Sheet 1 HIS ATTORNEY Patented July 18, 1972 3,677,656

3 Sheets-Shae t 2 32 K 33 W 7 I K! "ME 41,, 32 f Fig. 4. 26' 23 2e 1 I i INVENTOR.

BY EUGENE [VI/Buck I8 MW HIS ATTORNEY Patented July 18, 1972 3,677,656

3 Sheets-Sheet 4 I INVENTOR.

4 BY EUGENEW BUCK Fi 5 H/S ATTORNEY RADIAL POSITIONER, LOCK AND ROTARY CONTACTS FOR ELECTROMAGNETIC DRILL MOUNT BACKGROUND I obstructing use of the drill and difficulty in manipulating the same.

The present invention seeks to alleviate the limited swing afforded by the known rotary mounts relative to the magnetic base and to provide a Iockin g means which requires no special machining of the existing base or parts thereof. It further contemplates a locking means disposed on the drill support for rotary movement with the drill and spaced or offset therefrom to permit hand adjustment of the drill bit and manipulation of the locking means without interference of one with the other. In this connection it is an object to provide such rotary mount with means permitting lateral shifting as well as rotary movement between the drill support and magnetic base.

Accordingly, it is an object of the present invention to provide a locking means for such rotary mount offset from the drill and movable with the drill support. In this connection it is a further object to provide a single bearing plate for the drill support and a pressure member having diametrically opposed dual acting pressure rollers for locking the bearing plate in a stationary condition relative to the magnetic base.

It is another object to provide a drill support facilitating unlimited rotary adjustment between a rotary mount and a fixed or electromatic base.

It is a further object to provide a drill supporting rotary mount adapted for unrestricted continuous turning movement, 360 degrees and beyond, relative to a magnetic base. In this connection it is a still further object to provide an electrical connection between electrical wiring in the fixed magnetic base and the electrical wiring movable with and in the drill support facilitating unrestricted rotation of an electrical circuit from a fixed base to the rotary drill support.

These and other objects of the present invention will become apparent in the following description and accompanying three sheets of drawing in which:

FIG. I is a fragmentary side view of an electromagnetic base for an electric drill embodying the Radial Positioner and locking means therefor of the present invention.

FIG. 2 is a section through the centerpost of FIG. I taken along line 2-2 thereof and at larger scale.

FIG. 3 is a horizontal section through FIG. 2 taken along line 3-3 thereof at smaller scale;

FIG. 4 is an exploded perspective view of the rotary positioner and locking means of FIGS. 2 and 3;

FIG. 5 is a top plan view of the parts of FIG. 4 assembled;

FIG. 6 is an enlarged section through the center post of the rotary mount and locking means assembly of FIG. 5 taken substantially along line 6-6 thereof; and

FIG. 7 is a horizontal section through a portion of FIG. 6 and taken substantially along line 7 thereof.

GENERAL DESCRIPTION Referring to FIG. 1 an electromatic drill mount generally designated I is shown to include a base 11 upon which a drill press standard I2 is pivotally connected by a rotary mount 14 to support an electric drill [3 for rotary and lateral movement about the center of the base ll. Within the base II is an electromagnet I which when energized causes the base 11 to become firmly set against any iron, steel or magnetically attractable surface 5 against which the base is placed.

DETAILED DESCRIPTION The rotary mount 14 consists of a center pin 16, a rotary bearing plate 17 and a locking means 20 for locking the plate 17 relative to the base 11. The center pin l6 has a reduced threaded end secured in a tapped bore I8 formed centrally in the flat top surface 19 of the base 11. The bearing plate I7 has an open center 21 fitting over the pin I6 such that the plate 17 lies flush, surface to surface, against the flat top I9 of the base II. The opening 21 in the plate 17 is of an elongated shape diametrically of the plate I7 to permit lateral shifting of the latter relative to the pin I6 and base 1 I.

The plate I7 is centered relative to the base 11 and pin I6 in one direction and laterally shiftable by reason of the long dimension of the opening 2I in the plate 17. As best seen in FIGS. 4, 6 and 7 the opening 2l is of a width slightly greater than the diameter of the center pin 16 and is centered relative thereto. The arrangement is such as to afford sliding fit of the pin I6 relative to the elongated opening 2] to thereby maintain the bearing plate centered in one direction and shiftable laterally by reason of the length of the opening 21 diametrically of the plate I7.

The locking means 20 includes a collar member 23 concentric of and fitting the pin 16. The collar member 23 rests upon the plate I7 and has a pair of recesses 24-24 formed on its upper edges diametrically opposite each other and each provided with a slanted bottom 25-25 forming a locking race on the top surface of the collar 23. These locking races 25-25 are disposed transverse to the elongated opening 21 in the plate [7, i.e., diametrically of the width thereof.

A pair of rollable members 26-26 are disposed in the recesses 24-24, respectively, and confined within a yoke 27 having a center opening circumscribing the pin 16 except for diametrically opposite recesses 28-28 in the yoke 27 for maintaining the rollable members on a locking race or slanted bottoms of the recesses 24-24. A flat race 29 having a center bore 30' fits over the center pin I6. The flat race 29 is secured against upward movement on the center pin I6 by a nut 30 on the threaded upper end of the pin I6 and to form an upper flange on the pin 16. The flat race 29 is thus disposed to rest upon the rollable members 26-26 which are of a diameter such as to maintain the flat race 29 in spaced relation to the upper end of the collar 23.

The extreme upper end of the center pin I6 has a rotatable extension 3I projecting therefrom into a guide 32 formed on an offset arm of the upper end of a rotor bracket 33. This bracket 33 has its lower end 34 secured by machine screws 35 to the bearing plate I7 to one side of the elongated opening 21. The yoke 27 (FIG. 6) is ofa thickness slightly less than the space between the flat race 29 and the locking race of the collar 23 so as to be free to rotate about the center pin 16.

As best seen in FIGS. 5 and 6 the guide 32 is in the form of an elongated slot 32', the side walls of which engage and guide flat sides of the otherwise round extension 31 on the pin l6. The slot 32 extends parallel to the long axis of the elongated opening 21 and is coordinated therewith to shift laterally of the pin 16 as the bearing plate 17 is similarly moved.

A lever type screw shank 36 has its inner end threaded through a boss 37 formed on one end of the yoke 27 axially of the diametrically opposite roller confining recesses 28-28 therein. This screw shank 36 extends from the yoke 27 in a direction opposite the rotor bracket 33 and has a handle 38 at its free end exteriorly of the drill support such that the screw shank can be manually turned to advance or withdraw its inner end toward and from the rollable members 26-26. The screw shank 36 extends through a grommet opening 39 in a casting cover 40 of the drill press standard 12 which is secured by bolts M to the rotary bearing plate 17. The arrangement is such that the yoke 27 and screw shank 36, although swingable relative to the drill mount 14 (FIG. 3), the handle 38 is always to one side of the drill I3 carried by the standard I2 as best illustrated in FIGS. 1. Thus it will be appreciated that the handled end 38 and screw shank 36 serves as a lever radially disposed to the drill mount I4 to enable manual turning of the latter relative to the magnetic base 11 without one obstructing the other. Once the drill 13 is set properly relative to the base ll the operator need only turn the handle 38 to advance the screw shank 36 radially inward relative to the yoke 27. The inner end of the screw shank is thus caused to bear against one of the roller members, namely 26 adjacent the same. In this manner, the distance is reduced between the end of the screw shank 38 and the recess 28' at the diametrically opposite end of the yoke. This causes both rollable members 26-26 to be drawn radially inward and upward the inclined bottoms in the recess 24-24 or locking race of the collar 23. The upper race 29 being fixed against upward movement by the nut 30 on the upper end of the pin 16, both rollable members 26-26 become cammingly jammed against the locking race in collar 23 and the latter forced downwardly upon the rotary bearing plate 17. Thus the bearing plate 17 is securely pressed against the top surface of the stationary base 11 and the drill mount l4 securely locked in the desired position of adjustment relative thereto.

As previously stated the rotary mount l4 is laterally shiftable as well as rotatable to afford a wide range of adjustment of the electrical drill [3 about the otherwise fixed electromagnetic base ll. As in all such electrically operated drill mounts electrical current is supplied by electrical conductive wires between the fixed base and the rotatable standard for the tool. In most cases, the degree of rotation must be limited to avoid undue twisting of such electrical conductors. in the present case, however, no limitation is required. The drill supporting standard 14 is free to turn continuously in any one direction by the provision of rotary electrical contacts 45 within the rotary mount l4.

Referring to FIGS 6 and 7 the rotary electrical contacts 45 are confined within the center pin 16 in substantially axial relation to the rotary mount l4. For this reason the pin 16 which is stationary and otherwise affixed to the electromagnetic base ll is hollowed out to receive and support the parts of the rotary electrical contacts 457 The reduced threaded end of the pin 16 has an axial bore 46, the lower end of which communicates with a lateral bore 47 in the base ll through which a pair of electrical conductor wires 48-48 extend from the electromagnetic coil l in the base ll. Above the axial bore 46 the pin 16 has a bore 49 of greater diameter providing a shoulder 50 adjacent the threaded lower end of the pin 16. This larger bore 49 is lined with a non-conductive sleeve 44.

A bottom contact support 51 of non-conductive material is disposed to rest upon the shoulder 50. This bottom support 51 has an upwardly extending reduced portion 52 upon which lower and upper contact plates 53 and 54 as parts of the rotary electrical contacts 45 are centrally mounted. The broad base of the bottom contact support 51 and its reduced portion 52 are bored axially to receive the fixed electrical conductors 48-48 coming from the fixed base ll. One electrical conductor wire 48 extends up through the extension 52 and is soldered to a center contact 55 resting upon the upper end of the extension 52.

The other fixed electrical conductor wire 48' passes through a radial groove 56 in the member 51 which is pressed fit and fixed in the center pin 16. The wire 48 is soldered to a depending ear 57 on the lower contact plate 53 keyed into an upper extension of the groove 56in the member 51.

Counterparts of the fixed electrical conductor wires 48-48 are similar rotary wires 58-58 respectively which extend up through the pin 16 and its rotary extension 31 for connection to the DC side of a rectifier (not shown) housed within the drill press casting 40 and connected to AC. power controls from a source of A.C. power in a conventional manner. These rotary wires 58-58 become a part of the rotatable side of the rotary electrical contacts 45. To this end the electrical conductor wire 58' is soldered to an ear 59 of the upper rotary contact plate 54 which ear 59 is keyed in a groove 60 extending upwardly in one side of an other wise round rotor body 617 The rotor body 61 which is made of a hard non-conductive material is mounted for rotation within the non-conductive sleeve 44 which is a lining in the larger bore 49. It is this rotor body 61 which has at its upper end the rotatable extension 31 previously mentioned as projecting into the guide slot 32' at the upper end of the rotor bracket 33. A non-conductive washer 16' provides electrical insulation between the pin 16 and the bracket 33. Thus the rotor body 61 is caused to rotate within the center pin 16 for turning the upper rotary contact plate 54.

The center contact of the rotary electrical contacts 45 is completed by a contact brush 62 having soldered connection to one end of the other one of the rotary electrical conductor wires 58 which extends up into the drill supporting standard l2 for connection to the rectifier as previously mentioned. To facilitate this connection the rotor body 61 has a lower bore 63 which fits over the upwardly extending reduced portion 52 of the bottom contact support 5i.

As best seen in FIG. 6 there is a slight clearance between the base end of the bore 63 and the center contact 55 resting on the upper end of the extension 52. From this base end of the bore 63 the non-conductive rotor body has a secondary bore 64 of lesser diameter to receive a compression spring 65. This secondary bore 64 is formed as a square to guide a contact brush 62 of square cross section in a conventional manner. The brush 62 is thereby formed for preventing turning of the brush 62 within the bore 64. The spring 65 rests against a shoulder 66 adjacent a final central bore 67 which extends up through the terminal end 31 of the rotor body 61. The brush 62 is thus pressed firmly against the center contact 55 and permitted to turn with the rotor body 61 as the upper end 31 of the body rides in the guide slot 32 of the rotary bracket 33.

As illustrated in FIGS. 6 and 7 the lower or fixed contact plate 53 is spring pressed toward the rotary contact plate 54 to maintain constant electrical connection between them despite their relative rotationv To this end the bottom contact support 51 has a plurality of recesses, preferably three, in which compression springs 68 are seated to bear upwardly against the fixed lower contact plate 53 and press the latter firmly against the upper rotary contact plate 54.

By the foregoing arrangement the rotary support for the drill press has unlimited rotatability relative to the electromagnetic base without fear of twisting the interconnected wiring therebetween. Moreover, with the lever means 36 extending in fixed radial relation to the rotary drill mount housing 40 and in offset relation to the drill supported thereon, manual shifting and rotation of the drill relative to the base ll is unobstructed. In addition to the foregoing with the handle 38 on the lever so disposed, locking of the drill mount relative to the base is easily accomplished by turning of the handle as described.

While I have described my improved radial positioner and locking means in specific detail it will be appreciated by those skilled in the art that the same may be varied and/or modified without departing from the spirit or scope of the appended claims.

What I claim as new and desire to protect by Letters Patent 1. In a portable electric drill of the type having an electromagnetic base adapted to be affixed to a surface worked upon and a drill press support for such drill mounted for rotation on said base, a radial positioner and locking means therefor comprising:

a. a center pin extending upwardly from said base;

b. a rotary bearing plate secured to the bottom of said drill press support and having an open center diametrically of and circumscribing said pin facilitating lateral and rotary movement of said plate relative to the upper surface of said base; and

c. a locking means comprising:

1. a lower race on said pin and resting upon said bearing plate; 2. a pair of rollable members mounted on said lower race;

3. a yoke circumscribing said pin and confining said rollable members diametrically opposite each other on said lower race;

4. an upper race resting on said rollable members and limited against upward movement on said center pin; and

S. lever means threadedly connected to said yoke for radial movement toward and from said pin to force said rollable members inwardly relative to said pin to thereby urge said lower race downwardly against said bearing plate and into locked engagement against the upper surface of said base.

2. The device in accordance with that of claim 1 in which said lever means extends radially from said yoke substantially at a right angle relative to the drill press on the drill press support for turning the latter about said pin, and in which said lower race has a pair of opposite recesses diametrically aligned with said lever means for supporting said rollable members in fixed relation to said lower race for turning the latter and said rotary bearing plate upon rotative manipulation of said lever means about said center pin.

3. The device in accordance with that of claim 2 in which the open center of said rotary bearing plate is elongated diametrically thereof for guiding said bearing plate for lateral shifting movement relative to said center pin.

4. The device in accordance with that of claim 3 including:

a. an extension on the upper end of said center pin, and

b. a rotor bracket mounted on said rotary bearing plate and having an elongated guide slot formed on its upper arm parallel to the elongated opening in said rotary bearing plate for receiving and guiding the upper extension on said pin during lateral and rotary movement relative to said center pin.

5. The device in accordance with that of claim 4 including:

a. a non-conductive rotary body mounted concentrically of said center pin for turning movement therein and forming a part of said extension on the upper end of said pin;

b. said extension having flattened opposite sides thereon guidedly engaging the side walls of the elongated guide slot on said rotor bracket to thereby turn said rotary body relative to said center pin upon rotary adjustment of said rotary bearing plate; and

. rotary electrical contacts within said rotary body for electrically connecting the electrogagnet in said base relative to a source of power control on said rotary drill press support.

6. The device in accordance with that of claim 5 in which said rotary electrical contacts comprises:

a. fixed electrical conductors between the electromagnet in said base and said center pin;

b. fixed center and peripheral contacts connected to said fixed electrical conductors within said center pin;

c. rotary center and peripheral electrical contacts in electrical contact with said fixed center and peripheral contacts within said center pin and keyed to said non-conductive rotary body mounted therein for turning movement therewith; and

d. rotary electrical conductors connected to said rotary center and peripheral electrical conductors and extending upwardly through said rotary body for connection to the source of electrical control on said rotary drill press support.

7 The device in accordance with that of claim 6 in which said center pin has a non-conductive sleeve lining circumscribing said non-conductive rotary body therein.

8. The device in accordance with that of claim 7 including:

a. a lower contact support fixedly mounted in said center pin within the non-conductive sleeve lining therein, said lower contact support having a reduced portion extending upwardly therefrom for receiving and supporting said fixed and rotary peripheral contacts concentrically within said sleeve lining;

b. means for keying said fixed peripheral contact to said lower contact support; and g c. means for keying said rotary peripheral contact to said non-conductive rotary body for turning movement therewith within said non-conductive sleeve lining in said center pin.

9. The device in accordance with that of claim 8 including spring means within said lower contact support for urging and maintaining said fixed and rotary peripheral contacts in electrically conductive contact with each other.

10. The device in accordance with that of claim 9 in which said fixed center contact is mounted on the upper end of the reduced portion of said lower contact support and said rotary center contact is mounted in the lower end of said non-conductive rotary body; and spring means within said non-conductive rotary body for urging and maintaining said rotary center contact in electrically conductive contact with said fixed center contact.

11. in a portable electric drill of the type having an electromagnetic base adapted to be afiixed to a surface worked upon and a drill press support for such drill mounted for rotatable adjustment on said base. the combination comprising a member attached to said magnetic base extending into the bottom of said drill press support, means clamping said drill press support to said magnetic base, said member having insulation means supporting a first pair of electrical contacts in fixed relation to said magnetic base, means connecting said electrical contacts to a coil in said magnetic base, a second insulation means supporting a second pair of electrical contacts, means attaching said second insulation means to said drill press support, one of said second pair of electrical contacts being in rotatable contact with one of said first pair of electrical contacts and the other of said second pair of electrical contacts being in rotatable contact with the other of said first pair of electrical contacts, means for connecting said second pair of electrical contacts to a source of current supply to energize said coil through the circuit including said pairs of contacts so that said drill press support may be adjusted on said magnet base after said coil in said magnet base is energized and before said drill press support is clamped to said magnet base by said clamping meansv i l II l 

1. In a portable electric drill of the type having an electromagnetic base adapted to be affixed to a surface worked upon and a drill press support for such drill mounted for rotation on said base, a radial positioner and locking means therefor comprising: a. a center pin extending upwardly from said base; b. a rotary bearing plate secured to the bottom of said drill press support and having an open center diametrically of and circumscribing said pin facilitating lateral and rotary movement of said plate relative to the upper surface of said base; and c. a locking means comprising:
 1. a lower race on said pin and resting upon said bearing plate;
 2. a pair of rollable members mounted on said lower race;
 3. a yoke circumscribing said pin and confining said rollable members diametrically opposite each other on said lower race;
 4. an upper race resting on said rollable members and limited against upward movement on said center pin; and
 5. lever means threadedly connected to said yoke for radial movement toward and from said pin to force said rollable members inwardly relative to said pin to thereby urge said lower race downwardly against said bearing plate and into locked engagement against the upper surface of said base.
 2. a pair of rollable members mounted on said lower race;
 2. The device in accordance with that of claim 1 in which said lever means extends radially from said yoke substantially at a right angle relative to the drill press on the drill press support for turning the latter about said pin, and in which said lower race has a pair of opposite recesses diametrically aligned with said lever means for supporting said rollable members in fixed relation to said lower race for turning the latter and said rotary bearing plate upon rotative manipulation of said lever means about said center pin.
 3. The device in accordance with that of claim 2 in which the open center of said rotary bearing plate is elongated diametrically thereof for guiding said bearing plate for lateral shifting movement relative to said center pin.
 3. a yoke circumscribing said pin and confining said rollable members diametrically opposite each other on said lower race;
 4. an upper race resting on said rollable members and limited against upward movement on said center pin; and
 4. The device in accordance with that of claim 3 including: a. an extension on the upper end of said center pin, and b. a rotor bracket mounted on said rotary bearing plate and having an elongated guide slot formed on its upper arm parallel to the elongated opening in said rotary bearing plate for receiving and guiding the upper extension on said pin during lateral and rotary movement relative to said center pin.
 5. The device in accordance with that of claim 4 including: a. a non-conductive rotary body mounted concentrically of said center pin for turning movement therein and forming a part of said extension on the upper end of said pin; b. said extension having flattened opposite sides thereon guidedly engaging the side walls of the elongated guide slot on said rotor bracket to thereby turn said rotary body relative to said center pin upon rotary adjustment of said rotary bearing plate; and c. rotary electrical contacts within said rotary body for electrically connecting the electrogagnet in said base relative to a source of power control on said rotary drill press support.
 5. lever means threadedly connected to said yoke for radial movement toward and from said pin to force said rollable members inwardly relative to said pin to thereby urge said lower race downwardly against said bearing plate and into locked engagement against the upper surface of said base.
 6. The device in accordance with that of claim 5 in which said rotary electrical contacts comprises: a. fixed electrical conductors between the electromagnet in said base and said center pin; b. fixed center and peripheral contacts connected to said fixed electrical conductors within said center pin; c. rotary center and peripheral electrical contacts in electrical contact with said fixed center and peripheral contacts within said center pin and keyed to said non-conductive rotary body mounted therein for turning movement therewith; and d. rotary electrical conductors connected to said rotary center and peripheral electrical conductors and extending upwardly through said rotary body for connection to the source of electrical control on said rotary drill press support.
 7. The device in accordance with that of claim 6 in which said center pin has a non-conductive sleeve lining circumscribing said non-conductive rotary body therein.
 8. The device in accordance with that of claim 7 including: a. a lower contact support fixedly mounted in said center pin within the non-conductive sleeve lining therein, said lower contact support having a reduced portion extending upwardly therefrom for receiving and supporting said fixed and rotary peripheral contacts concentrically within said sleeve lining; b. means for keying said fixed peripheral contact to said lower contact support; and c. means for keying said rotary peripheral contact to said non-conductive rotary body for turning movement therewith within said non-conductive sleeve lining in said center pin.
 9. The device in accordance with that of claim 8 including spring means within said lower contact support for urging and maintaining said fixed and rotary peripheral contacts in electrically conductive contact with each other.
 10. The device in accordance with that of claim 9 in which said fixed center contact is mounted on the upper end of the reduced portion of said lower contact support and said rotary center contact is mounted in the lower end of said non-conductive rotary body; and spring means within said non-conductive rotary body for urging and maintaining said rotary center contact in electrically conductive contact with said fixed center contact.
 11. In a portable electric drill of the type having an electromagnetic base adapted to be affixed to a surface worked upon and a drill press support for such drill mounted for rotatable adjustment on said base, the combination comprising a member attached to said magnetic base extending into the bottom of said drill press support, means clamping said drill press support to said magnetic base, said member having insulation means supporting a first pair of electrical contacts in fixed relation to said magnetic base, means connecting said electrical contacts to a coil in said magnetic base, a second insulation means supporting a second pair of electrical contacts, means attaching said second insulation means to said drill press support, one of said second pair of electrical contacts being in rotatable contact with one of said first pair of electrical contacts and the other of said second pair of electrical contacts being in rotatable contact with the other of said first pair of electrical contacts, means for connecting said second pair of electrical contacts to a source of current supply to energize said coil through the circuit including said pairs of contacts so that said drill press support may be adjusted on said magnet base after said coil in said magnet base is energized and before said drill press support is clamped to said magnet base by said clamping means. 